Where the Red Fern Grows. It's a classic and is something they wouldn't pick up on their own. Yes, I know it's sad, but it also has some great teaching moments in there as it talks about hard work, cost of things a long time ago, etc...

I start the year with Hoban's The Mouse and His Child- figurative language, foreshadowing, motif and symbolism, incredible characterization- AMAZING teaching tool. (Not to mention, the opportunity to do many "voices.")

I second Where the Red Fern Grows and add the classic The Secret Garden.